In order to form integrated circuits on wafers, lithography process is used. A typical lithography process involves applying a photo resist, and defining patterns on the photo resist. The patterns in the patterned photo resist are defined in a lithography mask, and are defined either by the transparent portions or by the opaque portions in the lithography mask. The patterns in the patterned photo resist are then transferred to the underlying features through an etching step, wherein the patterned photo resist is used as an etching mask. After the etching step, the patterned photo resist is removed.
With the increasing down-scaling of integrated circuits, high aspect ratio stacking of layers used in photo patterning techniques can lead to poor wiggling resistance during pattern transfer to an amorphous silicon substrate. Line wiggling can, in turn, lead to pattern defects. Pattern defects and line wiggling can result in in breaking metal pattern lines and cause the pattern to fail.